Seven seems to be the magic number for TNT’s series Rizzoli & Isles, which has just started its final season on the cable network.

Rizzoli & Isles, based on the novels by Tess Gerritsen, has had a good run on TNT, never finishing lower than fifth among scripted cable series in the Nielsen ratings, and averaging four million viewers a week, according to reports.

While I will be sorry to see this series end when this 13-episode seventh season concludes, let’s celebrate what Rizzoli & Isles has meant to viewers and readers.

Aside from the attention it has brought to Gerritsen’s bestselling novels and their entertaining and interesting plots, Rizzoli & Isles helped usher in TNT’s movies based on other mystery writers’ novels.

While we are not seeing any more of these movies, which included works by Mary Higgins Clark, Lisa Gardner, and Richard North Patterson, it was good while it lasted.

But Rizzoli & Isles gave us something else even more important—an involving look at the power of female friendships.

I believe in female friendships—there is indeed a power, a love, a support system that emerges when women are true friends. I have been blessed with several close women friends and I value each of them.

These two women are very different—the tough Rizzoli and the cerebral Isles came from different backgrounds, had different interests, and even different tastes in men.

But they each had a strong respect for each other, their mutual skills and for their differences. They were not jealous of each other, and neither tried to outshine the other. When one was concerned about the other’s behavior, she said so and did her best to support and help her friend.

Too often female friends on TV exist only in sitcoms, and then one is always trying to outdo the other, whether in men, position, or even wardrobe.

Rizzoli & Isles had none of that. Even when Rizzoli or Isles wore low-cut clothes, it wasn’t their physical attributes that were on display but their intelligences.

The last time we had such a female buddy duo in a drama was the wonderful series Cagney and Lacey that starred the incomparable Sharon Gless as Det. Christine Cagney and Tyne Daly as Det. Mary Beth Lacey. (A highlight a couple of years ago was sitting with my husband as he interviewed Sharon Gless who was starring in the play A Round-Heeled Woman at GableStage in Coral Gables, Florida. And yes, she was nice and funny and down to earth.)

Rizzoli & Isles also showed that friendships can be stretched and even severed, and yet also strengthened by a separation, another thing the series shared with Cagney and Lacey when Mary Beth became fed up with Christine’s drinking.

The problem was more severe with Rizzoli & Isles. At the end of the second season, Jane shot Maura’s father, an Irish mobster. Maura only recently has learned about their relationship. Eventually, of course, the two women learned to trust each other again.

Rizzoli & Isles will celebrate its 105th episode after this final season. That is a magic number for syndicate as it means we will be seeing these two for several years in reruns.

Several years ago, I interviewed by Angie Harmon and Sasha Alexander before the series was to be launched. Harmon told me that she had read all of Gerritsen’s novels. It was interesting to play her character at a different time in her life than in the novels.

“You’re sitting here watching these two characters live, but if you know the books you know what happens to them before they know what happens to them,” said Harmon at the time. (The interview is here.)

Gerritsen has told me how pleased she has been with the series though in her imagination neither Jane nor Maura were as glamorous looking as Harmon and Alexander.

So enjoy Rizzoli & Isles as it winds down. And also enjoy Gerritsen’s novels, which are still going strong.